Reliability Modeling of Phased Mission System with Phase Backup by Stochastic Petri Net

This paper presents a modeling method by stochastic Petri net for reliability analysis of phased mission system( PMS) with phase backup. The model consisting of petri nets,depicts the system behaviors of unit level,system logic level and phase level. Guard functions of petri nets are used to avoid modeling complexity and make the model flexible to different reliability logical structures. It was shown that the time redundancy within phase and from phase backup for PMS can both be described by use of the proposed model.

Global Mission Sensitivity Study for Phased MissionSystem with Analysis of Variance Method

A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phased mission systems( PMS). The simulation strategy of GMS based on a Petri net and Monte Carlo method was presented which had broad applicability. Finally,the GMS and Birnbaum's sensitivity of components in a PMS example were compared. The GMS of component is demonstrated to be more adaptable to reflect the component mission sensitivity when the rated reliability parameters of components cannot be obtained, and components have state dependency or the system is subjected to common cause failure.

Reliability simulation and analysis of phased-mission system with multiple states

Basing on discrete event simulation, a reliability simulation algorithm of the phased-mission system with multiple states is put forth. Firstly, the concepts and main characters of phasedmission system are discussed, and an active and standby redundancy (AS) tree structure method to describe the system structure of each mission phase is brought forward. Secondly, the behavior of the phased-mission system with multiple states is discussed with the theory of state chart. Thirdly, basing on the discrete event simulation concept, a simulation algorithm to estimate reliability parameters of the phased-mission system with multiple states is explored. Finally, an example is introduced and analyzed, and the analysis result verifies the algorithms. The simulation algorithm is practical and versatile, for it can model complex behavior of phased-mission system flexibly, and more reliability parameters to understand system operation can be attained.

Analysis of Phased-Mission System Reliability and Importance with Imperfect Coverage

Accounting for static phased-mission systems (PMS) and imperfect coverage (IPC), generalized and integrated algorithm (GPMS-CPR) implemented a synthesis of several approaches into a single methodology whose advantages were in the low computational complexity, broad applicability, and easy implementation. The approach is extended into analysis of each phase in the whole mission. Based on Fussell-Vesely importance measure, a simple and efficient importance measure is presented to analyze component’s importance of phased-mission systems considering imperfect coverage.

多阶段任务系统(PMS)可靠性模型研究

多阶段任务系统(phased mission system,PMS)包含了一系列具有时间连续且不相互覆盖的基本任务阶段。针对系统特点,对PMS的两种可靠性模型进行了初步的讨论和分析,并提出了一种对包含可修任务的PMS系统可靠性评估的方法。该方法从任务可靠度的角度描述了系统的可靠性,并结合可用度、可信度等描述参数建立了新的评估模型。最后从理论上分析了此方法的可行性,并通过实例验证了其有效性和正确性。

基于Extend的多态PMS仿真模型

针对现有解决多态多阶段任务系统(PMS)的方法存在过程复杂、缺乏统一排序的问题,以最小割集为基础,提出基于Extend的多态PMS仿真模型。通过结构函数表达各阶段的逻辑关系,在已知基本设备失效分布函数的情况下,利用抽样统计思想处理多态PMS中的阶段依赖和模式依赖关系。相比DEP-BDD解析算法,应用该模型求解PMS能在保证可靠度误差较小、稳定性较好的基础上,使建模分析过程更简单。

航天发射场PMSCM任务可靠性仿真评估

为了解决航天发射场复杂可维修多阶段任务系统(phased-mission system,PMS)的任务可靠性评估问题,依据考虑维修的多阶段任务系统(phased-mission system considering maintenance,PMSCM)理论和蒙特卡罗方法,基于系统特殊的任务成功定义规则,通过任务阶段的形式化描述与零部件的虚节点处理,建立可靠性评估仿真模型。将模型应用于航天发射场垂直总装厂房液压系统,成功分析了系统多阶段任务的可靠性均值、方差和置信区间。仿真结果表明:该模型能够找出系统的关键部件,为垂直总装厂房及航天发射场系统总体任务进行可靠性预计、分配和评估提供重要参考和决策支持。

基于备件方案的多态PMS可靠性仿真模型

针对多阶段任务系统(PMS)的备件问题,构建基于Monte Carlo方法的仿真模型,给出具体的算法流程。该模型以多态结构函数为基本输入,产生等价于基本设备寿命实现值的随机数,代入仿真模型,经过逻辑运算和统计分析得到系统的可靠度,为多态PMS的备件决策提供依据。应用Matlab软件进行仿真实验分析,结果表明该方法具有较高的仿真精度。

PMS故障树分析中的变量排序策略库研究

研究阶段任务系统(PMS)故障树变量排序方法。构造一个包含10种不同排序策略的策略库,基于实例基准测试对策略库中的单个策略进行平均性能分析,并在此基础上对策略库本身进行互补性和完备性分析。实例分析表明,应用该策略库可以为各种结构特征的大规模PMS故障树快速有效地生成系统二进制决策图。

基于PMS理论的常规潜艇任务可靠性研究

针对常规潜艇功能复杂、任务多变的特点,将多阶段任务系统(phased mission system,PMS)理论引入到其任务可靠性的分析中。深入分析常规潜艇的鱼雷攻击任务,建立任务可靠性模型,用马尔可夫过程法进行了任务可靠度计算,为常规潜艇任务可靠性模型的建立提供一种新方法。

一种考虑共因失效的PMS可靠性建模分析方法

共因失效(CCF)打破了系统内组件失效的独立性假设,会对系统特别是多阶段任务系统(PMS)的可靠性评估产生显著影响。针对多阶段任务系统中随机共因失效(PCCF)对任务可靠性的影响问题,对共因事件之间的关系进行分析,利用贝叶斯理论扩展了共因事件的概率模型,使其适用于互斥、相互独立和统计相关等多种统计关系。在此基础上提出了综合应用二元决策图(BDD)和马尔可夫(Markov)模型的模块化建模分析方法。首先,利用故障树对任务过程建模;然后,在考虑共因失效的情况下采用BDD和Markov模型分别计算系统中静态模块和动态模块;再次,由全概率公式计算任务可靠性;最后,以卫星首次转轨过程为对象,验证了方法的有效性,并通过与已有案例的对比,分析了共因失效对任务可靠性的影响。

Approximate Method for Reliability Assessment of Complex Phased Mission Systems

Phased-mission systems (PMSs) have wide applications in engineering practices, such as manmade satellites. Certain critical parts in the system, such as cold standby, hot standby and functional standby, are designed in redundancy architecture to achieve high reliability performance. State-space models such as Markov process have been used extensively in previous studies for reliability evaluation of PMSs with dynamic behaviors. The most popular way to deal with the dynamic behaviors is Markov process, but it is well known that Markov process is limited to exponential distribution. In practice, however, the lifetime of most machinery products can follow non-exponential distributions like the Weibull distribution which cannot be handled by the Markov process. In order to solve this kind of problem, we present a semi-Markov model combined with an approximation algorithm to analyze PMS reliability subjected to non-exponential failures. Furthermore, the accuracy of the approximation algorithm is investigated by comparing to an accurate solution, and a typical PMS (attitude and orbit control system) is analyzed to demonstrate the implementation of the method. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

基于三角直觉模糊数的多阶段任务系统可靠性评估

针对多阶段任务系统(Phased Mission System,PMS)可靠性评估中对系统或部件退化规律认识不清、主观知识不完备、环境变化等原因造成部件的信息不足或不精确问题,基于三角直觉模糊数(Triangular Intuitionistic Fuzzy Number,TIFN)和二元决策图(Binary Decision Diagram,BDD)模型,提出了一种PMS可靠性评估方法。首先,定义了TIFN的指数运算法则,证明了其满足的性质;其次,通过多位专家对部件平均故障时间(Mean Time to Failure,MTTF)进行评估,利用TIFN量化专家意见,建立了直觉模糊失效率评估模型,构建了一种计算TIFN的隶属度和非隶属度的方法,根据TIFN的运算法则和指数分布函数定义了部件的模糊失效函数;最后,运用示例说明了该方法的有效性,并与传统PMS-BDD方法、模糊故障树方法和直觉模糊故障树方法进行了对比分析。

基于贮存剖面的弹上电子部件可靠性分析

目的提高弹上电子部件贮存可靠性预测的准确度,提出基于贮存剖面的弹上电子部件可靠性分析方法。方法在分析弹上电子部件贮存剖面及环境条件的基础上,将弹上电子部件视为多阶段任务系统,引入贝叶斯分析,采用分阶段建模方法,针对各阶段相关性和失效率的不同,基于累积损伤模型,构建弹上电子部件贮存寿命周期内的可靠性模型。结果相比于洞库贮存、值班等单一环境条件下的可靠性预测,基于贮存剖面综合环境下的可靠性预测结果的准确性更高,且随着贮存时间的增长,优势更明显。结论该方法立足于实际贮存剖面,分析结果更符合弹上电子部件的应用实际,也为其他弹上部件的可靠性分析提供了一种有效途径。

Simplified Markov Model for Reliability Analysis of Phased-Mission System Using States Merging Method

This paper presents a simplified Markov model to evaluate the reliability of phased-mission system(PMS). The time cost and storage requirement are very huge for traditional Markov model to analyze the PMS reliability as the number of components increases to a large scale. The states merging method proposed in this paper can account for the PMS with subsystems consisting of identical components, and similar PMSs are common in real-world systems. The simplified Markov model by states merging has smaller number of system states, compared with the traditional one. Furthermore, for the above subsystems, the size of our model increases only linearly as the number of components increases, while the size of the traditional model exponentially increases.Finally, the effectiveness and correctness of our approach are analyzed by comparing with the traditional Markov method.

考虑阶段备份的多态多阶段任务系统可靠性建模方法

近些年来,由于在航空航天、分布式计算以及核电系统等系统中广泛的应用,多阶段任务系统(phased mission system, PMS)可靠性理论与方法得到了广泛的关注与研究。在现代航天系统,尤其是载人航天系统,为了使整个系统的任务可靠性更高,经常会采用任务备份的方法来提高系统的任务可靠性。针对该类型的问题,提出一种基于多态多值决策图(multistate multi-valued decision diagram, MMDD)的方法。首先,将阶段故障树模型转化为阶段模型,其次,根据阶段代数方法将阶段模型融合为系统模型。在阶段模型融合过程中,通过增加随机变量的方法对单元经历的阶段进行统计,从而实现降低所建立的系统模型大小,提高建模效率,并以某型航天器推进子系统为例对建模方法进行说明。

基于动态贝叶斯网络的多阶段任务系统维修优化

针对多阶段任务系统各部件及不同阶段间的相关性,提出了一种多阶段任务系统维修优化的方法。该方法采用4种具有不同有效性测度的维修策略,使得在维修活动尽可能少的情况下获得了较高的任务可靠性;利用动态贝叶斯网络来表征多阶段任务系统各部件及不同阶段间的相关性,在使用隐马尔可夫模型对性能退化部件进行量化的同时,基于观测数据实现了对部件的状态及退化速率的同步更新。

考虑冲击与阶段备份的多阶段任务系统可靠性建模

近年来,由于在航空航天、军事、核能等领域的广泛应用,多阶段任务系统(phased mission system,PMS)可靠性建模方法得到了广泛的关注。航天系统所包含的电子设备会由于自身的老化导致性能退化而失效,同时也会因为外界的随机冲击导致失效,严重影响系统可靠度。针对该问题,提出一种基于模块化方法的模型。首先,将冲击模型与半马尔可夫过程结合,计算受冲击影响的工作单元可靠度。然后,提出一种基于二元决策图(binary decision diagram,BDD)模型的方法,对同时考虑冲击与阶段备份的PMS进行可靠性建模。最后,以某型航天器中的推进子系统为例对所提方法进行说明,并应用蒙特卡罗方法进行验证,证明了所提方法的建模效率与准确性。

多阶段任务系统任务持续能力仿真模型研究

多阶段任务系统(PMS)是一种典型的复杂系统,它包括多个在时间上连续且无相互重叠的阶段任务,执行作战与使用任务的武器装备多数属于这种复杂系统。分析了PMS及任务可靠度、可信度和任务效能等任务持续能力评价参数。结合实际装备系统大都属于可用马尔可夫过程进行描述的可修复系统的特点,为简化模型复杂程度提出了一些合理的假设条件。在此基础上,结合多阶段任务系统自身特点,通过分析多阶段任务系统任务持续能力建模仿真步骤,多阶段任务系统任务效能仿真方法,建立了基于Petri网的多阶段任务系统任务效能多层仿真模型。最后结合常见的"靶场打靶"任务进行了实例验证,并对仿真结果进行了分析。

复杂作战任务弹药配备模型

多阶段任务系统(PM S)是一种典型的复杂系统,它包括多个在时间上连续且无相互重叠的基本任务,武器系统的作战过程多数属于这种复杂系统。以某作战单元的一次作战任务流程为例,详细地讨论了多阶段复杂任务系统的特点,并从基本任务阶段的系统可信性、可用度的角度出发,分析了在满足给定火力指标的前提下,建立整个复杂作战任务流程中弹药配备模型的方法。